| 摘要 |
PURPOSE:To make a photographing system small in size by providing a lens group for executing a movement for the purpose of variable power to an object side and an image side of an optical path splitting means, on a photographic lens, and also providing a lens group for executing a movement at the time of variable power in order to compensate a movement of a focal plane, on a finder optical path. CONSTITUTION:An intermediate lens group 12 of a photographic lens 10 shares a part of a positive power of a front moving lens group 11 so that a rear moving lens group 13 is in a position separated from an optical path splitting block, and also decreases a moving extent of the lens group 13 by earning a magnification so that the optical path splitting block 14 and the lens group 13 do not cause a mechanical interference. Also, a compensating lens group 17 is provided on a finder optical path which has been split by the block 14, moves along the optical axis by synchronizing with a movement of the moving lens groups 11, 13 of the photographic lens 10, and compensates a movement of an image surface which has been caused by the lens group 11. That is to say, the lens group 17 always positions an image of an object to be photographed, on a primary image forming surface 18, and also changes a magnification in accordance with a variation of the magnification of the photographic lens 10. In this way, a photographing system can be made small in size.
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